Chinese MysterysnailViviparus malleatus Japanese MysterysnailV. japonicusThe Chinese mysterysnail (Viviparus malleatus) and The Japanese
mysterysnail (V. japonicus) are two very similar species.
Both introduced species are larger than the native species and their shells
lack the color banding typical of native species. They have a smooth
shell that is thin in structure, but strong. Color is uniform, light to
dark olive-green, without any color bands. These snails can usually
be found partially buried in the mud or silt of lakes, ponds, irrigation
canals, and roadside ditches or slow streams. They prefer quiet water
where there is some vegetation and a mud bottom. A large Chinese
mysterysnail can reach 65mm in length with 6 or 7 whorls on their shells.
This species is native to Burma, Thailand, South Vietnam, China, Korea,
and Asiatic Russia in the Amur region, Japan, the Philippines, and Java.
It is suspected that introduction into the United States was from accidental
or intentional releases from the aquarium industry.